Data/hora: 26/09/2024 10:48:29

Biblioteca(s): 	Embrapa Soja.	
Data corrente: 	06/04/2004	
Data da última atualização: 	27/07/2007	
Autoria: 	TOLEDO, A. M.; HOFFMANN-CAMPO, C. B.; MIYAKUBO, S. H.; PIUBELLI, G. C.	
Título: 	Time of response and quantification of isoflavone in soybean genotypes after damage by Piezodorus guildinii.	
Ano de publicação: 	2004	
Fonte/Imprenta: 	In: WORLD SOYBEAN RESEARCH CONFERENCE, 7.; INTERNATIONAL SOYBEAN PROCESSING AND UTILIZATION CONFERENCE, 4.; CONGRESSO BRASILEIRO DE SOJA, 3., 2004, Foz do Iguassu. Abstracts of contributed papers and posters. Londrina: Embrapa Soybean, 2004.	
Páginas: 	p. 218.	
Série: 	(Embrapa Soja. Documentos, 228).
	
Idioma: 	Inglês	
Notas: 	Editado por Flávio Moscardi, Clara Beatriz Hoffmann-Campo, Odilon Ferreira Saraiva, Paulo Roberto Galerani, Francisco Carlos Krzyzanowski, Mercedes Concordia Carrão-Panizzi.	
Conteúdo: 	The induction of response to herbivory by production de novo or by augmentation of constitutive chemical compounds has been reported in various plants. Previous experiments carried out at the Embrapa Soybean Phytochemistry Laboratory, Londrina, PR, Brazil showed an increase in isoflavone content (induction) in some soybean genotypes after being damaged by Nezara viridula, as well as its negative effect on the insect feeding preference. Experiments were performed to evaluate the response time and the production of the isoflavones daidzin and genistin by several resistant genotypes (PI 229358, PI 171451, PI 274454, 'BRSMG 68', 'IAC 100'), as compared to a susceptible genotype ('Embrapa 4'). In the greenhouse, four P. guildinii (starved for 24h) were placed in cages (made from two Petri dishes bottoms) containing two soybean pods settled in a live plant of each tested genotype; insect-free cages were maintained as a control. After 18h of confining, the insects were removed from the cages and the pods were excised at 3, 7 and 15 days after herbivory (DAH) for seed extract preparation. An aliquot of the extract of each genotype was analyzed by HPLC to estimate the concentration of daidzin and genistin comparing with those obtained from pure compounds (standards). In general, the constitutive concentration of genistin (non-injured) was higher than daidzin in most of the tested genotypes. The maximum concentration of genistin in non-injured seeds was observed at 15 DAH, indicating an increase in this isoflavone concentration at the later stages of plant development. The injured and non-injured seeds of most genotypes produced the same amount of daidzin with exception of PI 171451 and 'BRSMG 68' at 3 and 7 DAH, respectively. At 15 DAH the concentration of genistin in the non-injured seeds was higher than in the injured seeds, with the exception of the genotype PI 274454. On the other hands, a gradual increase of daidzin concentration was observed over the time, mainly in injured seeds. At 3 DAH, the concentration of daidzin raised from 0.005, in non-injured to 0.169 mg/mL in injured seeds. However the most evident response was observed in the genotype 'BRSMG 68', at 7 and 15 DAH; daidzin concentration in injured seeds increased about three times (from 0,066 to 0,217 mg/mL and 0.087 to 0.229), compared with non-injured seeds. The results indicated that isoflavone concentration depends on the time, stage of plant development, genotype and may be induced by insect damage.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Soja (CNPSO)	
Exemplares: 	CNPSO - (23736-1) - UMT - PL - -- - RF 633.34072 - W927a -  - DIS